Creativity is aided by prompts and constraints; in fact it could be argued that the core of any game lies in its particular arrangement of prompts and constraints.  Even the most accomplished authors rarely pull a character out of their heads, fully-formed, all at once.  This is why, when writing the CORE system (for DayTrippers) I built “Progressive Character Generation” into the rules.  Sure, you are free to predefine everything about your character if you wish, but it often makes more sense to let them develop “organically” via interactions with other fictional elements.

Here’s how I put it in the DayTrippers Core Rules: “At the start of their career – just like the protagonists of most books and movies – you don’t really know very much about your DayTrippers character. Sure, you have Stats, some Skills, a little Gear, a few ideas about appearance, and maybe even a little personality.  But the real character of the character – the stuff that really makes the character tick – is usually a mystery at the start.

You know what?  That’s fine!  We don’t need to know their whole life story yet; we’re interested in what they’re doing right now.  We’ll get to know your character more deeply over time just as you do: by watching them in action, by observing the choices they make, by getting accustomed to their style… and once in a while –perhaps once per session – we’ll learn a little more about them in a special scene.”

And from the DayTrippers GameMasters Guide: “There’s no requirement for Players to spend all their Character Points prior to the beginning of play; in fact it’s smart to withhold a few and allow for Character Development to progress over the first few adventures.

This solves a perennial problem in roleplaying games: It’s all well and good to have Players create the important aspects of their own characters’ pasts – perhaps even neighboring details, like mentors, family and associated characters – but it’s entirely another thing to put them on the spot before play, forcing them to marry themselves to a character concept they haven’t even spent any quality time with yet.
We’ll get to know this character in their present-day context, from the outside in, the same way we get to know real people.  We’ll learn more about their past as it is revealed to us.”

Again, this is up to the Player – they can predefine if they want to; but it’s much more interesting for those who don’t.  If you’re okay with major revelations coming to light about television protagonists mid-season (say perhaps in a flashback scene), this is essentially the same thing.